315 research outputs found
Analysis of instability causes in the bi-dc converter and enhancing its performance by improving the damping in the IDA-PBC control
The poor damping of bidirectional dc (bi-dc) converter caused by constant power load makes power system prone to oscillation, and non-minimum phase characteristic also jeopardises voltage stability. To solve these challenges, the interconnection and damping assignment passivity-based control (IDA-PBC) is utilised to improve transient response. The influences of the right-half-plane (RHP) zero on the stability margin and controller design are illustrated by zero dynamics analysis. Then the port-controlled Hamiltonian modelling is used to obtain the IDA-PBC control law, which is suitable to the bi-dc converter and independent of the operation mode. The system dissipation property is modified, and thus the desired damping is injected to smooth the transient voltage. To remove the voltage error caused by RHP zero and adjust the damping ratio, an energy controller with an adjustment factor is introduced. Besides, a virtual circuit is established to explain the physical meaning of the control parameter, and the parameter design method is given. Passivity analysis assesses the controller performance. Simulation results are analysed and compared with other control strategies to test the proposed IDA-PBC strategy
A review of a translational sociology: interdisciplinary perspective on politics and society
A Translational Sociology—Interdisciplinary Politics and Society by Esperança Bielsa in 2023 has aroused our great interest, as the title has explicitly indicated a further fulfillment and development of Translational Sociology from the perspective of interdisciplinary politics and society. The recent decade witnesses how Translational Sociology is well-received in China, the further exploration of translation and society, translation and politics, translation and experience in this book enables more teachers, researchers, and postgraduates in translation study to be fully aware of the diversity, complexity, and modernity of translation as a social practice. Moreover, by reinforcing the core role of translation in mediating language differences in all aspects of social life, questioning simplistic views of cultural homogenization, probing into the identity and transformation, politics and democracy, and the nature of modern experience in translating, this book updates our comprehension of the global characteristics of contemporary society from the perspective of translation study
Gene expression analysis of induced pluripotent stem cells from aneuploid chromosomal syndromes
BACKGROUND: Human aneuploidy is the leading cause of early pregnancy loss, mental retardation, and multiple congenital anomalies. Due to the high mortality associated with aneuploidy, the pathophysiological mechanisms of aneuploidy syndrome remain largely unknown. Previous studies focused mostly on whether dosage compensation occurs, and the next generation transcriptomics sequencing technology RNA-seq is expected to eventually uncover the mechanisms of gene expression regulation and the related pathological phenotypes in human aneuploidy. RESULTS: Using next generation transcriptomics sequencing technology RNA-seq, we profiled the transcriptomes of four human aneuploid induced pluripotent stem cell (iPSC) lines generated from monosomy Ă— (Turner syndrome), trisomy 8 (Warkany syndrome 2), trisomy 13 (Patau syndrome), and partial trisomy 11:22 (Emanuel syndrome) as well as two umbilical cord matrix iPSC lines as euploid controls to examine how phenotypic abnormalities develop with aberrant karyotype. A total of 466 M (50-bp) reads were obtained from the six iPSC lines, and over 13,000 mRNAs were identified by gene annotation. Global analysis of gene expression profiles and functional analysis of differentially expressed (DE) genes were implemented. Over 5000 DE genes are determined between aneuploidy and euploid iPSCs respectively while 9 KEGG pathways are overlapped enriched in four aneuploidy samples. CONCLUSIONS: Our results demonstrate that the extra or missing chromosome has extensive effects on the whole transcriptome. Functional analysis of differentially expressed genes reveals that the genes most affected in aneuploid individuals are related to central nervous system development and tumorigenesis
An inertia-emulation-based cooperative control strategy and parameters design for multi-parallel energy storage system in islanded DC microgrids
This paper proposes an inertia-emulation-based cooperative control strategy for the multi-parallel energy storage system (ESS) to meet the requirements of state-of-charge (SoC) balance, inertia enhancement and zero-steady-state voltage deviation. The inertia emulation loop (IEL) is constructed by analogy with DC motors to dampen voltage oscillation, while the secondary voltage recovery loop is derived from the circuit equivalence of an inductor to indicate the system stiffness. Moreover, to equalize SoCs of energy storage units (ESUs) dynamically, a SoC self-balance algorithm is developed. The redefined SoC mismatch degree and balance speed adjustment factor k are introduced into the droop resistance, adjusting the SoC self-balance rate and eliminating the SoC deviation among ESUs. The dynamic performance of the SoC self-balance algorithm is analyzed and the small signal model of the DC microgrid (DC-MG) with proposed strategy is established. Based on eigenvalue analysis and step response, the system stability is assessed, and the influence of control parameters on transient characteristics and stability margin is investigated. Considering power constraint, voltage deviation constraint and dynamic stability constraint, the optimal design method of k is given. Finally, simulation and experiment verify that the proposed control, without modifying hardware, performs better dynamic and static characteristics and can equalize SoC among ESUs in charge and discharge mode
Disorder-induced phase transitions in double Weyl semimetals
The double Weyl semimetal (DWSM) is a newly proposed topological material
that hosts Weyl points with chiral charge n=2. The disorder effect in DWSM is
investigated by adopting the tight-binding Hamiltonian. Using the transfer
matrix method and the noncommutative Kubo formula, we numerically calculate the
localization length and the Hall conductivity in the presence of the on-site
nonmagnetic disorder or orbital (spin-flip) disorders, and give the
corresponding global phase diagrams. For the on-site nonmagnetic disorder, the
system undergoes the DWSM-3D quantum anomalous hall (3D QAH) and normal
insulator (NI)-DWSM phase transitions, and evolves into the diffusive metal
(DM) phase before being localized by strong disorders, which is consistent with
the Weyl semimetal. For \sigma_x orbital disorder, we find that increasing
disorder can generate a pair of Weyl nodes at the boundary of the Brillouin
zone and induce a 3D QAH-DWSM phase transition. Then we investigate the
combined effect of orbital disorders for both disordered 3D QAH phase and DWSM
phase. The disorder-induced transitions can be well understood in terms of an
effective medium theory based on self-consistent Born approximation.Comment: 8 pages, 9 figure
Spatial and temporal characteristics of carbon emission and sequestration of terrestrial ecosystems and their driving factors in mainland China—a case study of 352 prefectural administrative districts
IntroductionGlobal climate change, increase in human activities, and prominence of ecological issues have led to uneven quantitative and spatial distributions of carbon emission and sequestration of terrestrial ecosystems. Such uneven distributions can lead to more negative impacts on the natural environment and human living conditions.MethodsTherefore, based on the carbon neutralization policy, we conducted geographically weighted regression (GWR) modeling in this study using panel data from 352 Chinese prefectural administrative districts in 2000, 2005, 2010, and 2017 to analyze and determine the impact factors and their spatial distribution for carbon emission and sequestration of terrestrial ecosystems.ResultsOur results showed that total population (TP), per capita gross domestic product (GDP) (PCG), proportion of secondary industry output (PSIO), scale of urban built-up area (SUB), green space proportion in city areas (GSP), normalized difference vegetation index (NDVI), and temperature (TEM) are factors driving carbon sequestration and carbon emission. The spatial distribution of these driving factors in mainland China is: (1) TP showed a negative correlation to carbon emission in most areas, while it exhibited a positive correlation to carbon sequestration in the southern, southwestern, and western parts of northwest China; however, in all other areas, TP showed a negative correlation with carbon sequestration; (2) PCG was positively correlated to carbon emission in most areas of China and to carbon sequestration in southwest, south, central, and northeast China; however, PCG demonstrated a negative correlation to carbon sequestration in the remaining areas; (3) PSIO and SUB presented a positive correlation to carbon emission and a negative correlation to carbon sequestration in most areas; (3) In contrast, GSP showed a negative correlation to carbon emission and a positive correlation to carbon sequestration in most areas; (5)NDVI showed a negative correlation to carbon emission and carbon sequestration in most areas toward the east of the “Heihe-Tengchong Line”; NDVI was positively correlated to both carbon emission and sequestration toward the west of this line; (6)TEM was positively correlated to carbon emission and sequestration in most parts of China.DiscussionBased on these results, we further divided the Chinese cities into 6 groups: (1) Groups 1, 2, 3, and 6 are areas where carbon emission and sequestration are governed by both socioeconomic and natural ecological factors. The major driving factors of carbon emission and carbon sequestration in group 1 are PSIO, GSP, and NDVI; the driving factors of group 2 are SUB and NDVI. Meanwhile, carbon emission and sequestration in group 3 are governed by PCG, GSP, and NDVI; for group 6, carbon emission and sequestration are controlled by PCG, SUB, GSP, and NDVI; (2) Group 4 represents areas where carbon emission and sequestration are majorly impacted by PCG and SUB, thereby rendering socioeconomic factors as the major driving forces. Group 5 represents areas where carbon emission and sequestration are sensitive to the natural environment, with GSP and NDVI being the driving factors. Considering the uneven distribution of carbon sequestration and emission and the diverse driving factors in different areas of China, we provided guidance for future environmental policies aimed at reducing the uneven distribution of carbon sequestration and emission in different areas to achieve carbon neutralization
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